Knockout bar assembly for presses

ABSTRACT

A press having a front and a back defining a first pair of opposite sides, and a right and a left defining a second pair of opposite sides, includes a reciprocating slide. An elongated knockout bar is movably mounted in the slide for upward and downward movement relative thereto. The knockout bar has a longitudinal axis extending in the direction between one of said pair of opposite sides. A knockout bar operating device is located on the other pair of opposite sides for moving the knockout bar downward relative to the slide during upward movement of the slide.

United States Patent Keithley et a1.

[ 1 Oct. 24, 1972 [54] KNOCKOUT BAR ASSEMBLY FOR PRESSES [72] Inventors: Harry E. Keithley, Battle Creek; Robert A. Helrigel, Hastings, both of [21 App1.No.: 159,219

[52] [1.5. CI. ..100/2l8, 72/345, 72/427, 83/127, 83/135 [51} Int. Cl. ..B30b 15/32 [58] Field of Search ...100/218; 72/345, 427; 83/125, 83/127,135,136

[56] References Cited UNITED STATES PATENTS 3,364,721 1/1968 Criblez 72/345 3,561,245 2/1971 Hollenbeck ..72/ 345 FOREIGN PATENTS OR APPLICATIONS 240,810 6/ 1965 Austria ..100/21 8 Primary Examiner-Robert L. Bleutge Att0meyMeyer, Tilberry and Body ABSTRACT A press having a front and a back defining a first pair of opposite sides, and a right and a left defining a second pair of opposite sides, includes a reciprocating slide. An elongated knockout bar is movably mounted in the slide for upward and downward movement relative thereto. The knockout bar has a longitudinal axis extending in the direction between one of said pair of opposite sides. A knockout bar operating device is located on the other pair of opposite sides for moving the knockout bar downward relative to the slide during upward movement of the slide.

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ATTORNEYS PATENTEDUCT 24 1972 SHEEI 2 BF 4 INVENTOR.

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ATTORNEYS PATENTEDncI 24 I972 SHEET t [If 4 v OE INVENTOR. HARRY E. KEITHLEY ROBERT A. HELRIGEL BY Mam, 714W, 8 804,

ATTORNEYS KNOCKOUT BAR ASSEMBLY FOR PRESSES BACKGROUND OF THE INVENTION This application pertains to the art of presses and more particularly to a knockout bar arrangement for presses. The invention is particularly applicable to use with multiple station or progressive die presses although it will be appreciated that the invention has broader applications and may be used in other environments.

Presses having a multiple station die arrangement often require a plurality of individual knockout bars, with one bar being used for each die station. Each knockout bar requires separate operators which must be adjusted and synchronized. Obtaining proper adjustment of each knockout bar so that it will be synchronized with others for ejecting workpieces at the same time from each die station is extremely difficult.

SUMMARY OF THE INVENTION A knockout bar arrangement for a press includes elongated knockout bar means movably mounted on a press slide for upward and downward movement relative thereto. The knockout bar means has a longitudinal axis extending in a direction between a first pair of opposite sides on the press. Knockout bar operating means is located on another pair of opposite sides of the press for moving the knockout bar means downward relative to the slide during upward move-' ment of the slide.

In accordance with one arrangement, the knockout bar means has opposite knockout bar end portions and an elongated cross bar is connected to each of the opposite knockout bar end portions. Each elongated cross bar has opposite cross bar end portions and a pair of elongated connecting bars connect the cross bars at the cross bar end portions. Taken together, the knockout bar means, cross bars and connecting bars define a movable knockout assembly.

In a preferred arrangement, guide means is provided for guiding the knockout assembly during movement thereof relative to the slide. In one arrangement, the cross bars have holes in the opposite end portions thereof and the slide has a plurality of upstanding pins thereon extending through the holes. This guides the knockout assembly during upward and downward movement thereof.

The knockout assembly includes biasing means for biasing the knockout assembly upward relative to the slide. In one arrangement, the biasing means comprises counterbalancing air cylinders connected to the end portions of the connecting bars.

In a preferred arrangement, the operating means for moving the knockout assembly downward relative to the slide comprises cam and cam follower means on the slide and on the press frame. The cam and cam follower means is adjustable for moving the knockout bar assembly downward at a desired point during the upward movement of the slide.

It is a principle object of the present invention to provide an improved knockout bar arrangement for presses.

It is also an object of the present invention to provide a knockout bar assembly which is economical to manufacture and assemble.

It is a further object of the present invention to provide a knockout bar assembly which is simple and reliable in operation.

DESCRIPTION OF THE DRAWING The invention may take form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawing which forms a part hereof. I

FIG. 1 is a side elevational view of a press having the improvement of the present invention incorporated therein;

FIG. 2 is a cross-sectional plan view looking in the direction of arrows 2-2 of FIG. 1;

FIG. 3 is a cross-sectional elevational view looking in the direction of arrows 33 of FIG. 2; and

FIG. 4 is a front elevational view looking in the direction of arrows 4-4 of FIG. 3 and with portions cut away for clarity of illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, FIG. 1 shows a press A having four upstanding posts 12 located at the comers of a rectangle for guiding a slide 8 in vertical reciprocating movement. Press A includes a bed 14 on which a die 16 is adapted to be mounted for cooperation with a die 18 attached to slide B in a known manner. Slide B is connected with an eccentric 20 by connection 22. Eccentric 20 is driven by a motor 24 connected with flywheel 26 through belt 28. As best shown in FIG. 2, press A has a first pair of opposite sides defined by a front 32 and a rear 34. Press A further has a left side 36 and a right side 38 defining a second pair of opposite sides for press A. Guides 40 are attached to post 12, and gibbing 42 is positioned between guides 40 and slide B for guiding slide B during reciprocating movement thereof.

In one arrangement, slide B has a pair of elongated spaced-apart slots 46 therein. It will be recognized that only one slot may be provided if so desired and that more than two slots may also be provided depending upon the number of knockout bars which are required for the particular application involved. Slots 46 are elongated in a direction extending between opposite sides 36 and 38 of press A. Reciprocatingly mounted for vertical up and down movement relative to slide B and elongated slots 46 are knockout bars 48. Knockout bars 48 are elongated and have longitudinal axes extending in a direction between opposite sides 36 and 38 of press A.

In one arrangement, a pair of spaced-apart parallel bars D, which may be termed either guide bars or cross bars, have the intermediate portions 52 thereof connected with the opposite end portions of knockout bars 48 by bolts 54. Bolts 54 extend upward through suitaend portions 56 of bars D by being welded or otherwise secured thereto as at 62. Other connecting bar E inter connects end portions 58 of cross bars D as by being welded or otherwise secured thereto at 64. As shown in FIG. 2, connecting bars E extend substantially perpendicular to cross bars D. Taken together, knockout bars 48, cross bars D and connecting bars E define a knockout assembly which is movable up and down relative to slide B.

In a preferred arrangement, guide means is provided for guiding the knockout assembly during up and down movement thereof relative to slide B. In one arrangement, four vertical pins 68 are secured to slide B. Pins 68 extend through holes 70 formed in the opposite end portions of cross has D. With holes 70 slidably received over pins 68, the knockout assembly is slidably guided for accurate up and down movement relative to slide B.

In a preferred arrangement, biasing means is provided for biasing the knockout assembly upward relative to slide B. In one arrangement, opposite end portions 60 of connecting bars E have substantially L- shaped brackets G bolted or welded thereto as shown in FIG. 4. Brackets G have substantially horizontal arms 74 extending in line with connecting bars E. Pressurized air cylinders H are mounted on slide B and have rod ends 76 thereof extending through suitable holes in arms 74 and connected thereto as by bolts 78. Air cylinders H are connected through conduits with a pressure source andsurge tank in a known manner for normally biasing upwardly against brackets G. This biasing force is in turn transmitted to the entire knockout assembly defined by connecting bars E, cross bars D and knockout Bars 48.

Operating means is provided for moving the knockout assembly downward relative to slide B during upward reciprocating movement of slide B. In one arrangement, the operating means is defined by cam and cam follower means mounted on the frame of press A and on slide B. Substantially horizontal mounting beams 82 and 84 extend across front and rear sides 32 and 34 of press A. Mounting beams 82 and 84 are secured to legs 12 as by bolts 86. A cam mounting bracket I is attached to each of mounting beams 82 and 84. Each cam mounting bracket I includes a vertically extending keyway 88 having a rectangular cross-sec tional shape. Enlarged rectangular heads 90 of bolts 92 are received in keyways 88 so that earn mounting brackets I may slide vertically relative to bolts 92. Bolts 92 extend through suitable holes in mounting beams 82 and 84, and have nuts 96 threaded on the ends thereof for tightly drawing cam mounting brackets I against mounting beams 82 and 84 to prevent vertical movement of cam mounting brackets I. Each cam mounting bracket I has an elongated adjustment rod 102 attached thereto as by bolts 104 and 106. The bottom ends of pins 102 bear against the upper edges of mounting beams 82 and 84. Nuts 96 on bolts 92 may be loosened so that cam mounting brackets I are free to move relative to bolts 92. Adjustment of nuts 104 and 106 will then move cam mounting brackets I upward or downward relative to mounting beams 82 and 84 for properly positioning a cam carried by cam mounting brackets I to move knockout bars 48 downward at a desired point during the upward stroke of slide B. Each cam mounting bracket I includes a cam member I secured thereto as'by bolts 112 extending through suitable holes in cam member .I and threading into threaded bores in cam mounting brackets I. Each cam member J includes an inclined cam face 1 14.

In one arrangement, cam follower members are mounted on slide B adjacent front and rear sides 32 and 34 of press A. Cam follower mounting brackets K may be bolted or otherwise secured to slide B. Each cam follower mounting bracket K includes a-pair of spacedapart upstanding ears 114. An elongated shaft 116 spans ears 114 and is received in holes formed therein. Shaft 116 is non-rotatably held to ears 114 as by set screw means indicated at 1 18 in FIG. 4. A cam follower member L is mounted on each shaft 116 for rotation relative thereto as on sleeve bearings 120.

In one arrangement, each cam follower member L includes a central upstanding arm 124 and a pair of spaced-apart substantially horizontal arms 126. A nose portion 128 on each horizontal arm 126 bears against hardened wear plates 130 releasably attached to the upper surfaces of connecting bars E as by suitable screws extending through holes in wear plates 130 and threaded into threaded bores in connecting bars E. Each upright arm 124 has a roller 132 rotatably mounted thereon as by pins 134.

It will be recognized that knockout bars 48 act against knockout pins which extend through the bolster, die carrier and die for knocking workpieces from the die during upward reciprocating movement of slide B. In operation of the device, the knockout assembly defined by knockout bars 48, cross bars D and connecting bars E is normally biased upward to the solid line position shown in FIG. 3 and the dotted line position shown in FIG. 4. The knockout assembly remains in the solid line position due to the biasing of air cylinders I-I during the downward terminal work stroke of slide B. Upon upward movement of slide B, rollers 132 on upright arms 124 of cam follower members L strike against sloping faces 1 14 of cam members J. Cam follower member L on the left hand side of FIG. 3 is then pivoted clockwise, while cam follower member L on the right hand side of FIG. 3 is pivoted counterclockwise. Nose portions 128 of horizontal arms 126 then push downward on connecting bars E to force knockout bars 48 downward to the shadow line position shown in FIG. 4 for acting against knockout pins to forcing workpieces from the dies. Once rollers 132 have again passed below cam surfaces 114 on cam members J during downward movement of slide B, air cylinders H will return the knockout assembly to its uppermost position with knockout bars 48 located in the solid line position shown in FIG. 3. Upward movement of slide B will again cause knockout bars 48 to move downward to the shadow line position for again moving the knockout pins down during the upward stroke of slide B.

While the invention has been shown and described with reference to a preferred embodiment, it is obvious that alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the claims.

Having thus described our invention, we claim:

1. In a press having a front and a back defining a first pair of opposite sides and a right and a left defining a second pair of opposite sides, said press having reciprocating slide means reciprocable upward and downward for operating on workpieces, elongated knockout bar means movably mounted in said slide means for upward and downward movement relative thereto, said knockout bar means having a longitudinal axis extending in a direction between one of said pair of opposite sides, and knockout bar operating means located on the other of said pair of opposite sides for moving said knockout bar means downward relative to said slide means during upward movement of said slide means, said knockout bar means having opposite knockout bar end portions, an elongated cross bar connected to each of said opposite knockout bar end portions, each of said elongated cross bars having opposite cross bar end portions, a pair of elongated connecting bars connecting said cross bars at said cross bar end portions, said cross bars and connecting bars together defining a rectangle and being movable with said knockout bar means, and said operating means acting against said connecting bars to move said knockout bar means.

2. The device of claim 1 wherein said knockout bar means, cross bars and connecting bars define a movable knockout assembly, and guide means for guiding said assembly during movement thereof relative to said slide means.

3. The device of claim 2 wherein said guide means includes a plurality of pins mounted on said slide means at least certain of said cross bars and connecting bars having holes therein slidably receiving said pins.

4. The device of claim 3 wherein said holes are in said opposite end portions of said cross bars.

5. The device of claim 3 and further including biasing means for biasing said knockout assembly upward relative to said slide means.

6. The device of claim 2 and further including biasing means for biasing said knockout assembly upward relative to said slide means.

7. The device of claim 6 wherein said biasing means comprises counterbalancing air cylinders connected to certain of said cross bars and connecting bars.

8. The device of claim 7 wherein said cylinders are connected to said opposite end portions of said connecting bars.

9. The device of claim 1 wherein said press has a frame and said operating means comprises cooperating cam and cam follower means on said slide means and on said frame.

10. The device of claim 9 wherein said cross bars, connecting bars and knockout bar means defines a movable knockout assembly and means for biasing said assembly upward relative to said slide means.

1 1. A knockout bar assembly for a press comprising; a rectangular frame including a pair of elongated spaced-apart cross bars having opposite end portions and a pair of spaced-apart elongated connecting bars extending. perpendicular to said cross bars and interconnecting said cross bars at said opposite end portions thereof, said cross bars having intermediate portions, elongated knockout bar means having opposite end portions connected to said cross bars at said intermediateportions thereof and extending parallel to said connecting bars, a press slide, said assembly being 

1. In a press having a front and a back defining a first pair of opposite sides and a right and a left defining a second pair of opposite sides, said press having reciprocating slide means reciprocable upward and downward for operating on workpieces, elongated knockout bar means movably mounted in said slide means for upward and downward movement relative thereto, said knockout bar means having a longitudinal axis extending in a direction between one of said pair of opposite sides, and knockout bar operating means located on the other of said pair of opposite sides for moving said knockout bar means downward relative to said slide means during upward movement of said slide means, said knockout bar means having opposite knockout bar end portions, an elongated cross bar connected to each of said opposite knockout bar end portions, each of said elongated cross bars having opposite cross bar end portions, a pair of elongated connecting bars connecting said cross bars at said cross bar end portions, said cross bars and connecting bars together defining a rectangle and being movable with said knockout bar means, and said operating means acting against said connecting bars to move said knockout bar means.
 2. The device of claim 1 wherein said knockout bar means, cross bars and connecting bars define a movable knockout assembly, and guide means for guiding said assembly during movement thereof relative to said slide means.
 3. The device of claim 2 wherein said guide means includes a plurality of pins mounted on said slide means at least certain of said cross bars and connecting bars having holes therein slidably receiving said pins.
 4. The device of claim 3 wherein said holes are in said opposite end portions of said cross bars.
 5. The device of claim 3 and further including biasing means for biasing said knockout assembly upward relative to said slide means.
 6. The device of claim 2 and further including biasing means for biasing said knockout assembly upward relative to said slide means.
 7. The device of claim 6 wherein said biasing means comprises counterbalancing air cylinders connected to certain of said cross bars and connecting bars.
 8. The device of claim 7 wherein said cylinders are connected to said opposite end portions of said connecting bars.
 9. The device of claim 1 wherein said press has a frame and said operating means comprises cooperating cam and cam follower means on said slide means and on said frame.
 10. The device of claim 9 wherein said cross bars, connecting bars and knockout bar means defines a movable knockout assembly and means for biasing said assembly upward relative to said slide means.
 11. A knockout bar assembly for a press comprising; a rectangular frame including a pair of elongated spaced-apart cross bars having opposite end portions and a pair of spaced-apart elongated connecting bars extending perpendicular to said cross bars and interconnecting said cross bars at said opposite end portions thereof, said cross bars having intermediate portions, elongated knockout bar means having opposite end portions connected to said cross bars at said intermediate portions thereof and extending parallel to said connecting bars, a press slide, said assembly being movably mounted on said slide for up and down movement relative thereto, means for biasing said assembly upward relative to said slide, said slide being reciprocable up and down, and operating means for moving said assembly down relative to said slide during upward movement of said slide, said connecting bars having intermediate portions and said operating means acts against said intermediate portions of said connecting bars. 